Machine for winding wire into the form of straight-sided polygonal coils



June 21, 1955 GEQRG 2,711,007

MACHINE FOR WINDING WIRE INTO THE FORM OF STRAIGHT-SIDED POLYGONAL COILS Filed Sept. 17, 1954 2 Sheets-Sheet 1 H. P. GEORGH MACHINE FOR WINDING WIRE INTO THE FORM OF STRAIGHT-SIDED POLYGONAL COILS June 21, 1955 2 Sheets-Sheet 2 Filed Sept. 17, 1954 r wa w m M W WM H w United States Patent MACHINE FOR WINDING WIRE INTO THE FORM OF STRAIGHT-SIDED POLYGONAL COILS Hans Peter Georgii, Stockholm, Sweden Application September 17, 1954, Serial No. 456,663 Claims priority, application Sweden November 30, 1951 7 Claims. (Cl. 29-33) This invention relates to machine for winding wire into the form of straight-sided polygonal coils, and it comprises in combination a rotary mandrel or capstan, a plurality of peripherally spaced coil-supporting elements mounted on said mandrel in positions defining the shape of the polygonal coil to be wound, means for supplying wire under tension to said mandrel, means for rotating the mandrel against the tension of the wire, a wirebending means rotatably mounted at one side of the mandrel and having at least one arm adapted to enter the spaces between said coil supporting elements as these elements pass by during rotation of the mandrel, a percussion element or wire-bending element mounted on said arm adapted to bend the wire inwardly towards the axis of the mandrel along the sides of the polygon defined by said coil-supporting elements a distance slightly inside the perimeter of said polygon so that, upon release of the bending pressure, the inherent resilience of the wire causes it to spring back to form a straight side of the polygonal coil, and means for rotating said wire-bending element in correlation with the rotation of said mandrel so that the wire on each side of polygonal coil is straightened as it is wound; said wire bending means being advantageously mounted on a shaft parallel to the axis of the mandrel and having means for adjusting the effective lenght of said arm for winding wires of different properties; all as more fully hereinafter set forth and as claimed.

This application is a continuation-in-part of my copending application, Serial No. 322,415. In the prior application I described the basic principles of'my machine for winding wire into the form of straight-sided polygonal coils and illustrated it by a practical operating machine. In the present application I describe several modifications of the original machine which make it possible to wind polygonal coils of Widely different shape.

In the construction of reinforced concrete piles, pillers,

columns and the like it is conventional to provide reinforcing rods running longitudinally of these elements, in combination with helical wire coils for holding the rods together. These coils usually conform in shape to the cross section of the concrete elements to be constructed I and therefore usually have a polygonal cross section. The reinforcing rods are secured by the coils usually in the corners of the polygon. This type of reinforcement has been found to be highly satisfactory. But it has been found ditficult to construct the requiredhelical coils of wire having straight sides with plane surfaces.

The principal object of this invention is to provide a machine for winding the described polygonal wire coils and for bending the wire as it is wound into coils which have straight or plane sides. The invention can be adapted to the production of polygonal coils of widely different cross sections and of substantially any desired length.

A further object of the invention is to provide a. machine for the production of the described coils with a minimum 7 consumption of material and with improvement in the physical properties of the wire.

My invention can be described in greater detail by reference to the accompanying drawing which shows, more or less diagrammatically, several embodiments of my machine. In this showing,

Fig. 1 is a plan view of my machine,

Fig. 2 is a vertical section through the mandrel and wire bending means, taken along the line IIII of Fig. 1,

Fig. 3 is a plan view which shows a modified form of mandrel and wire bending means which can be used for winding a coil of rectangular cross section,

Fig. 4 is a plan view of another modification of a mandrel and wire bending means which can be used for winding a coil of hexagonal cross section,

Fig. 5 is still another modification of mandrel and wire bending means which can be used for winding a coil of triangular shape, while Fig. 6 is a partial view partly broken away to show the details of an adjustable percussion or wire-bending element adapted to change the effective length of a wirebending arm.

1n the various views like parts are designated by the same reference numerals. Referring first to Figs. 1 and 2, my machine comprises a frame 1 enclosing an electric motor 2. The motor drives a vertical shaft 4 journaled in the frame at a relatively low speed through worm gears 3. The shaft projects through a table or base 5 on which the winding mandrel or capstan 6 is mounted. The lower part of the mandrel is flanged, the flange being formed into a spur gear 7 which is provided with a slightly beveled upper rim 8. The mandrel has a substantially star-shaped cross section and it consists of a central hub 9 which is keyed to and mounted on shaft 4 and is provided with a plurality of circumferentially spaced radial fins or coil-supporting elements 10. These fins have sharp outer edges or extremities which define the corners of a polygon. The fins are tapered upwardly to a slight extent so that the wound coil moves automatically upwardly as it is being wound. The upper faces of the fins are provided with vertical holes 11 for the mounting of rods 12. These rods receive the wound turns of the coil during the winding operation and are positioned close to the extremities of the fins.

A wire-bending device shown generally at 34 is mounted on the base at one side of the mandrel. This is driven by spur gear 7 at the base of the mandrel which engages with a pinion 13 which is rotatably mounted on a fixed vertical shaft 14 secured in table 5. Wire-bending arm 15 is mounted on top of the pinion and rotates with it. A percussion or wire-bending element 16 is mounted at the outer end of the wire-bending arm. This percussion element may be a ball bearing mounted on a vertical pin, or it may be a pin only or an eccentric disc of hard metal and it may be rotatable or fixed in position. During rotation of the wire-bending arm the percussion element, as shown in Fig. 2, enters each of the spaces between the coil-supporting elements or fins a distance which is slightly inside the perimeter of the polygon. During this interval the percussion element bears against the wire and bends it to such a degree that, upon release of pressure, the wire springs outwardly due to its inherent resilience and assumes a straight line position thus forming a straight side of the polygon.

It is evident that in order to bend and straighten the wire on each side of the polygon the arm shown in Figs. 1 and'2 must make a complete revolution for each side of the polygon or for each fin of the mandrel. This is accomplished by use of a pinion having a number of teeth which is one-fourth the number on the gear 7. It is also important, of course, that the wire bending arm 15 cross theline joining the axes of the mandrel and of the wire-bending means at the moment when the facing side of the polygon'becomes substantially perpendicular to said line or at the moment that the fins are equally spaced from the bending arm. In other words the parts must be so constructed and arranged that the bending arm momentarily assumes a position perpendicular to each side of the polygon as these sides pass by. This bending arm is evidently adapted to bend the wire of polygonal coils in all cases wherein the sides of the polygon are of equal length, i. e. when the polygons are equilateral.

The iron wire which is used in making reinforcing coils for concrete varies considerably in diameter and often also in physical properties when purchased. The socalled mm. wire, for example, may vary in diameter between 5 and 6 mm. The physical properties varyin like degree. My invention provides a method of Winding such wire and simultaneously drawing it to a uniform diameter, whereby a saving in cost is realized, and simultaneously improving its physical characteristics by cold working.

It is obviously necessary, of course, to supply wire to the mandrel of any coil-forming machine under considerable tension. In the past this has been accomplished by various wire-straightening and braking devices. These devices have merely served to straighten the wire without changing its diameter or cold working it. I have discovered, however, that my winding mandrel can be advantageously combined with a wire drawing die. This die is placed between the spool of wire to be wound and my mandrel. It serves to produce a su'fiicient tension, to draw the wire to a uniform diameter and simultaneously to cold work the metal thereby improving its tensile strength and other physical properties. Moreover the drawing die serves as a highly effective means of adjusting the tension of the wire during the winding. Thus during the conventional drawing operation the drawing plate is perpendicular to the wire as it leaves the plate, i. e. the die is aligned with the wire. But I operate the plate so the axis of the die is placed at an adjustable angle to the direction of the drawn wire and have found that the greater this angle the greater the tension on the wire and, incidentally, the greater the amount of cold working performed on the metal. During the drawing of an over-sized wire the length of the wire is increased with a consequent saving in cost. It follows that my combination of a drawing die and coil-winding mandrel produces several highly favorable and novel results.

In Fig. l I have shown the drawing plate at '18 and the spool of wire to be drawn at 17. The drawing plate is fixed in a holder 19 which is pivotally mounted on base 5 so that the plate can be swung in a horizontal plane to vary the angle between the drawn wire 33 and the axis of the die. This adjustment can be made by means of the set-screw 20. A stationary scale 22 may be employed to measure the angle of setting of the drawing plate to the drawn wire. Since my winding device can be operated at relatively high speeds it is usually necessary to cool the drawing plate. This is accomplished by passing water through the plate by means of hose 23.

The drawing plate is placed slightly below the level of the upper face of gear wheel 7 so that the wire passes over and is guided by the beveled rim '8 on the gear. Another guiding element can be employed such as pin 21 mounted on the base.

In Figs. 3, 4 and 5 modifications of my win'din-gmandrel are shown by means of which polygonal coils of different shapes can be wound. 'The mandrel of 'Fig. l produces a square coil, that of Fig. 3 a rectangular coil, that of Fig. 4 a hexagonal coil having 3 of its sides shorter than the other three, while the mandrel of Fig. 5 .produces a coil having a cross section in the form of an isosceles triangle. It is evident from these figures that by modifying my machine in suitable manner coils of any polygonal shape can be produced provided that the polygons can be substantially inscribed within a circle. When the sides of the polygon are of unequal length more than one bending arm must be provided on the bending means. These arms are advantageously either integral or rigidly connected.

The several modifications shown in the figures of the drawing are identical except for the shapes and positions of the coil-supporting elements on the mandrels, the gear ratios between spur gears of the mandrels and the pinions. of the wire bending means, and the number, the lengths and the angles between the bending arms employed. Referring to Fig. 3, a mandrel 6a is shown whose extremities or coil-supporting elements 10a define a rectangle. The bending means 34a is provided with two arms 15a and 15b which are of difierent length and have axes which are aligned, i. e. 180 apart. The longer arm 15a bends the wire along the longer sides of the rectangle while the shorter arm bends the wire along the shorter sides. It is evident that in this embodiment the pinion 13a must make two revolutions for each revolution of the mandrel 6a and therefore that this pinion must have one-half as many teeth as the gear 711. The construction and operation of the device is otherwise identical to that of the modification shown in Figs. 1 and 2.

In the modification of Fig. 4 the coil supporting elements 10b define a hexagon having 3 long sides of equal length and 3 shorter sides of equal length, with a short side opposite each long side. The wire bending means 34]) again has two arms of unequal length spaced 180 apart and the pinion 13b in this modification has onethird the number of teeth of gear 7b. The wire bending means thus makes a complete revolution for every 2 sides of the polygonal coil. The wire bending means of this modification is evidently adapted to bend the wire of polygonal shaped coils having adjacent sides of unequal length, the polygon consisting of a multiple of said adjacent sides.

The modification of Fig. 5 is adapted to wind coils having a section in the shape of an isosceles triangle. For this purpose the coil-supporting elements 10c are positioned so as to define the desired shape. The wire bending means 340 in this modification is provided with three arms, one being shorter than the other two which are of equal length, the arms being positioned apart. In this modification the wire bending means makes one revolution for each revolution of the mandrel 6c and therefore the pinion has the same number of teeth as the gear is.

It a separate percussion or wire-bending element is provided on the arms of the wire bending arms it is desirable that this element be adjustable in order to adapt the device -to the winding of wires of different properties. Some wires must be bent to a greater degree than other wires, dependi ng upon their hardness, resilience, diameter etc. In Fig. 6 I have shown an adjustable percussion element or disc 16 .mounted at the end of bending arm 15. The disc is mounted eccentrically and upon its rotation the eifective length of arm 15 is thereby adjusted. The arm is provided with a conical bore 27 and this receives a correspondingly tapered pin 28 which may be integral with the percussion disc. The upper end of the pin is threaded and a lock nut 29 is provided which when tightened locks the percussion disc in desired position. It is evident, of course, that the pin 28 may be eccentric with respect to the percussion disc or that the latter may have an eccentric profile. The disc is advantageously cons'tructed'o'f hardened steel. It is a simple matter to adjust the position of the percussion disc on the arm so that it bends the wire the correct amount to produce a polygonal coil having straight sides.

The different modifications of my machine which have been described are operated in substantially identical manner. The first step is to thread the wire to be wound through the drawing die and up to the winding mandrel. The end of the wire is temporarily attached to one of the coil-supporting elements. The motor is then started so that the mandrel is set in rotation and several turns of the wire are wound around the mandrel while the wire bending means operates to straighten the wire by bending it inwardly towards the axis of the mandrel so that the coil assumes a polygonal shape corresponding to that defined by the coil supporting elements. After several coils are wound the temporary connection between the end of the wire and the coil-supporting element is removed. Owing to the cooperation of the coil supporting elements and the polygonal shaped coil no fastening is required for further winding. The turns first formed automatically move upwardly on the mandrel during the winding and then on to the rods 12. When the resulting polygonal coil has reached the desired length a few more turns are Wound and then the motor is stopped. The wire is cut 01f at the base of the coil, the coil is removed and then the machine is ready for a new coil to be wound. Thus the winding operation can be conducted on a subsantially continuous basis.

While I have described what I consider to be the most advantageous modifications of my wire winding machine it is obvious, of course, that many modifications can be made in the specific structures which have been described without departing from the purview of this invention. For example, if a rotary percussion element is employed, an adjustable mounting can be provided which will in eifect adjust the length of the wire bending arms. Various ways of driving the mandrel and the wire bending means can be employed provided that these driving means are correlated as described. The structures of the mandrel and of the coil supporting elements can, of course, be varied considerably. The wire bending means can be rotated in the same direction as the mandrel or in the opposite direction. Better results are obtained when the directions of rotation are opposite as in the modifications which have been described. Further modifications of my machine which fall within the scope of the following claims will be immediately evident to those skilled in this art.

What I claim is:

1. A device for bending wire into the form of helical polygonal coils having straight sides and suitable for use as reinforcing elements for concrete piles and the like, which comprises in combination a rotary mandrel, a plurality of peripherally spaced coil-supporting elements mounted on said mandrel in positions defining the shape of the polygonal coil to be wound, means for supplying wire under tension to said mandrel, means for rotating the mandrel against the tension of the wire, a wirebending means rotatably mounted at one side of the mandrel and having at least one arm adapted to enter the spaces between said coil supporting elements as these elements pass by during rotation of the mandrel, said wire bending arm comprisingan element adapted to bend the wire inwardly towards the axis of the mandrel along 9 the sides of the polygon defined by said coil-supporting elements a distance slightly inside the perimeter of said polygon so that, upon release of the bending pressure, the inherent resilience of the wire causes it to spring back to form a straight side of the polygonal coil, and means for rotating said wire bending arm in correlation with the rotation of the mandrel in such manner that said wire bending element crosses the line joining the axes of the mandrel and of the wire bending means substantially at the moment when this line bisects the facing side of the polygon during rotation thereof.

2. The device of claim 1 wherein said means for supplying wire under tension comprises a wire drawing die having an axis adapted to be set at an adjustable angle to the direction of the drawn wire in order to control the tension on the wire and improve its physical properties.

3. The device of claim 1 wherein said wire bending means comprises a single arm which makes a complete revolution for each side of the polygon, said polygon being equilateral.

4. The device of claim 1 wherein said wire bending means comprises two arms, one being shorter than the other, said wire bending means making a complete revolution as each pair of adjacent sides of the polygon pass by, said sides being of unequal length and the polygon consisting of a multiple of said adjacent sides.

5. The device of claim 1 wherein said wire bending means comprises three bending arms, one being shorter than the other two which are of equal length, and the bending means makes a complete revolution for each revolution of the mandrel, the coil-supporting surfaces defining an isosceles triangle.

6. The device of claim 1 wherein the wire bending means is rotated in a direction opposite to that of the mandrel.

7. A device for bending and winding wire into the form of helical polygonal coils having straight sides and suitable for use as reinforcing elements in concrete piles and the like, which comprises in combination a mandrel rotatably mounted on a shaft, a plurality of peripherally spaced coil-supporting elements mounted on said mandrel in positions defining the shape of the polygonal coil to be wound, means for supplying wire under tension to said mandrel, means for rotating said mandrel against the tension of the wire, a second shaft mounted at one side of the mandrel with its axis substantially parallel to the axis of said mandrel, at least one wire-bending element mounted for rotation on said second shaft, means for rotating said second shaft in correlation with the rotation of the mandrel, said rotating means being so correlated and said wire-bending element being so mounted that, as each side of the polygonal coil reaches the position in which it is substantially perpendicular to the line joining the axes of said shafts, a wire bending element crosses said line and bends the wire towards the axis of the mandrel a distance slightly inside the perimeter of the polygon so that, upon release of the bending pressure, the wire springs back to form a straight side of the polygonal coil.

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